Package structure of optical module

ABSTRACT

A package structure of an optical module includes: a substrate defined with a light-emitting region and a light-admitting region; a light-emitting chip disposed at the light-emitting region of the substrate; a light-admitting chip disposed at the light-admitting region of the substrate; two encapsulants for enclosing the light-emitting chip and the light-admitting chip, respectively; and a shielding layer formed on the substrate and the encapsulants and having a light-emitting hole and a light-admitting hole, wherein the light-emitting hole and the light-admitting hole are positioned above the light-emitting chip and the light-admitting chip, respectively. Accordingly, the optical module package structure simplifies a packaging process and cuts manufacturing costs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of co-pending application Ser. No.14/073,567, filed on Nov. 6, 2013, for which priority is claimed under35 U.S.C. §120; and this application claims priority of Application No.102126688 filed in Taiwan, R.O.C. on Jul. 25, 2013, under 35 U.S.C.§119, the entire contents of all of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to package structures, and moreparticularly, to a package structure of an optical module.

2. Description of Related Art

At present, an optical proximity sensing module is regarded as amainstream technology choice for use with the new-generation smartelectronic devices (such as smartphones). If the electronic device isbrought close to the human ear (for face recognition) or put in apocket, the optical proximity sensing module will turn off the screendisplay of the electronic device right away to save power and prevent aninadvertent touch on the screen display, thereby enhancing ease of use.The optical proximity sensing module comprises a light-emitting chip(such as a light-emitting diode, LED) for emitting a light beam. Thelight beam reflects off an object surface to fall on a light-admittingchip and convert into an electronic signal for subsequent processing.For instance, Taiwan patent M399313 discloses a proximity sensingpackage structure which comprises a base, a dam extending vertically andenclosing the base, and a lid disposed on the dam, so as to form areceiving space, wherein the receiving space has therein a partitionboard for dividing the receiving space, such that a light-emitting chipand a light-admitting chip can be separately disposed on a substrate toshun mutual light beam-related interference which might otherwise resultin deterioration of product performance.

However, due to technological development, portable devices (such assmartphones, digital cameras, and other electronic products) are inincreasingly wide use and have a trend toward reduction of weight andthickness, low costs, and high yield. However, the aforesaid patent isbecoming less effective in coping with the aforesaid trend.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a packagestructure of an optical module to simplify the packaging process and cutthe manufacturing costs.

In order to achieve the above and other objectives, the presentinvention provides a method for packaging an optical module, the methodcomprising the steps of:

(a) defining a light-emitting region and a light-admitting region on asubstrate;

(b) connecting electrically the light-emitting chip and light-admittingchip to the light-emitting region and the light-admitting region of thesubstrate, respectively;

(c) forming a transparent encapsulant on the light-emitting chip and thelight-admitting chip;

(d) forming an opaque shielding layer on the encapsulants and thesubstrate; and

(e) removing the shielding layer above the light-emitting chip and thelight-admitting chip.

The encapsulants and the shielding layer are formed by molding.

The encapsulants are substantially inverted T-shaped.

The removal of the shielding layer is achieved by polishing, wherein theshielding layer is polished until the protruding top ends of theencapsulants are exposed, respectively.

The electrical connection step is achieved by a wire bonding process anda die attaching process.

The method further comprises step (e) in which the optical modulepackaged by the step (a) through step (d) is cut or punched.

The present invention further provides a package structure of an opticalmodule, comprising a substrate, a light-emitting chip, a light-admittingchip, two encapsulants, and a shielding layer.

The substrate is defined with a light-emitting region and alight-admitting region.

The light-emitting chip is disposed at the light-emitting region of thesubstrate.

The light-admitting chip is disposed at the light-admitting region ofthe substrate.

The two encapsulants enclose the light-emitting chip and thelight-admitting chip, respectively.

The shielding layer is formed on the substrate and the encapsulants andhas a light-emitting hole and a light-admitting hole. The light-emittinghole and the light-admitting hole are positioned above thelight-emitting chip and the light-admitting chip, respectively.

The encapsulants and the shielding layer are made of a transparentopaque resin.

The substrate is a non-ceramic substrate made of an organic material,such as Bismaleimide Triazine.

Accordingly, an optical module package structure of the presentinvention is manufactured by removing a shielding layer above alight-emitting chip and a light-admitting chip and exposing top ends ofencapsulants only, thereby simplifying the packaging process and cuttingthe manufacturing costs.

To enable persons skilled in the art to gain insight into the framework,features, and objectives of the present invention and implement thepresent invention accordingly, the present invention is hereunderillustrated with a preferred embodiment and the accompanying drawingsand described in detail. However, the description below is merelyintended to illustrate the technical solution and features of thepresent invention and the embodiment thereof. All simple modifications,replacements, or constituent component sparing made, without goingagainst the spirit of the present invention, by persons skilled in theart after understanding the technical solution and features of thepresent invention should fall within the claims of the presentinvention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The technical contents and features of the present invention arehereunder illustrated with a preferred embodiment in conjunction withthe accompanying drawings, in which:

FIG. 1 is a top view of an optical module package structure according toa preferred embodiment of the present invention;

FIG. 2 is a cross-sectional view of the optical module package structuretaken along line 2-2 of FIG. 1 according to the preferred embodiment ofthe present invention; and

FIG. 3 is a schematic view of the process flow of a packaging methodaccording to the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION

Referring to FIG. 1 through FIG. 2, an optical module package structure10 provided according to a preferred embodiment of the present inventionresults from cutting a module from a typical package array and comprisesa substrate 20, a light-emitting chip 30, a light-admitting chip 40, twoencapsulants 50, and a shielding layer 60.

The substrate 20 is a non-ceramic substrate made of an organic material,such as Bismaleimide Triazine, and thus the substrate 20 incurs a lowmaterial cost. The substrate 20 is defined with a light-emitting region22 and a light-admitting region 24.

The light-emitting chip 30 and the light-admitting chip 40 undergo a dieattaching process and a wire bonding process so as to be disposed at thelight-emitting region 22 and the light-admitting region 24 of thesubstrate 20, respectively. The light-emitting chip 30 emits the lightbeam. The light-admitting chip 40 receives the light beam emitted fromthe light-emitting chip 30.

The encapsulants 50 are made of a transparent resin, such as atransparent epoxy resin. The encapsulants 50 enclose the light-emittingchip 30 and the light-admitting chip 40, respectively, by molding.

The shielding layer 60 is made of an opaque resin, such as an opaqueepoxy resin. The shielding layer 60 is formed on the substrate 20 andthe encapsulants 50 and has a light-emitting hole 62 and alight-admitting hole 64. The light-emitting hole 62 and thelight-admitting hole 64 are positioned above the light-emitting chip 30and the light-admitting chip 40, respectively.

Referring to FIG. 3, A through D, there is shown a schematic view of theprocess flow of a method for packaging an optical module according tothe present invention. The first step A involves defining thelight-emitting region 22 and the light-admitting region 24 on the singlesubstrate 20 of each substrate array and electrically connecting thelight-emitting chip 30 and the light-admitting chip 40 to thelight-emitting region 22 and the light-admitting region 24 of thesubstrate 20 by a die attaching process and a wire bonding process,respectively. The second step B involves forming a transparentencapsulant 50 on the light-emitting chip 30 and the light-admittingchip 40 by molding, so as to form a protective layer. The third step Cinvolves forming an opaque shielding layer 60 on the encapsulants 50 andthe substrate 20 by molding. The fourth step D involves removing theshielding layer 60 above the light-emitting chip 30 and thelight-admitting chip 40. Finally, the structure fabricated by theaforesaid steps undergoes a cutting process or a punching process toform a single module.

In the preferred embodiment of the present invention, the second step Bthrough the fourth step D comprise: aligning an inverted T-shaped diewith the light-emitting chip 30 and the light-admitting chip 40 andpositioning the inverted T-shaped die on the surface of the substrate20; filling the inverted T-shaped die with a transparent resin such thatthe transparent resin covers the chips 30, 40; removing the invertedT-shaped die as soon as the transparent resin sets so as to form thesubstantially inverted T-shaped encapsulants 50; positioning ahollow-cored die on the substrate 20; filling the die with an opaqueresin to thereby cover the encapsulants 50 completely with the opaqueresin such that the shielding layer 60 is formed as soon as the opaqueresin sets; and polishing the shielding layer 60 from the top andhorizontally to thin the shielding layer 60 gradually until theprotruding top ends of the encapsulants 50 are exposed, respectively, soas to form the light-emitting hole 62 and the light-admitting hole 64 inthe shielding layer 60.

In conclusion, the optical module package structure 10 of the presentinvention is characterized by forming the shielding layer 60 above thelight-emitting chip 30 and the light-admitting chip 40 by the first andsecond molding processes and then polishing the shielding layer 60 by apolishing process until the top ends of the encapsulants 50 are exposed,respectively, to form the light-emitting hole 62 and the light-admittinghole 64 in the shielding layer 60, thereby simplifying the packagingprocess and cutting the manufacturing costs.

Constituent elements disclosed in the aforesaid embodiment of thepresent invention are illustrative rather than restrictive of thepresent invention. The replacements or changes of other equivalentelements should still fall within the appended claims of the presentinvention.

What is claimed is:
 1. A package structure of an optical module,comprising: a substrate defined with a light-emitting region and alight-admitting region; a light-emitting chip disposed at thelight-emitting region of the substrate; a light-admitting chip disposedat the light-admitting region of the substrate; two encapsulants forenclosing the light-emitting chip and the light-admitting chip,respectively; and a shielding layer formed on the substrate and theencapsulants and having a light-emitting hole and a light-admittinghole, wherein the light-emitting hole and the light-admitting hole arepositioned above the light-emitting chip and the light-admitting chip,respectively.
 2. The package structure of claim 1, wherein theencapsulants and the shielding layer are made of a transparent opaqueresin.
 3. The package structure of claim 1, wherein the substrate is anon-ceramic substrate made of an organic material, such as BismaleimideTriazine.